12 Mar 2004
The pick of this week’s patent applications including a low macrobending loss fiber.
• Title: Low macrobending loss optical fiber
Applicant: Corning Incorporated, US
International application number: WO 2004/019089
Corning has come up with a way to produce a low macrobending loss optical fiber. Detailed in patent application WO 2004/019089, the US firm claims its fiber has a macrobending loss of less than 1 dB at 1550 nm for a bending radius of 32 mm as well as a cut-off wavelength between 870 and 970 nm. The author’s say the fiber’s core should have a refractive index profile of between 1.7 and 3.0 while the cladding region should have an outer radius in excess of 40 mm.
• Title: Method of breaking a brittle substrate
Applicant: Koninklijke Philips Electronics, the Netherlands
International application number: WO 2004/018144
Consumer electronics giant Philips is trying to patent a way to break brittle materials. The idea involves translating a laser beam across a substrate to heat up a thin strip of material. A cooling solution is then applied to the heated strip, which causes it to crack. Philips uses an aqueous surfactant solution to cool the heated area. “The surfactants will connect to the broken siloxane bonds inside the surface cracks and the required breaking load will remain constant over time,” say the application’s authors.
• Title: An arsenic meter
Applicant: The Trustees of Columbia University in the city of New York, US
International application number: WO 2004/019004
Patent application WO 2004/019004 describes a portable instrument that determines the concentration of arsenic present in water. Powered by batteries or solar cells, the kit uses an infrared LED and a photodiode. To test for arsenic, the inventors add molybdenum-based compounds, which selectively bind to arsenates and phosphates, to the water sample. The light absorbance of the sample is then compared to reference data. “The differential light absorbance of the two specimens is used to arrive at a quantitative value for the arsenic concentration in the water sample,” say the authors.